Article : Chemical reaction of soap-making process

Soap is one of the oldest known chemical compounds. Transparent soap has PH 9.34.Sabun itself is never actually found, but comes from the development of a mixture of alkali compounds and fat / oil. Soap making material consists of two types, namely raw materials and supporting materials. The raw materials in the manufacture of soap are oils or fats and alkaline compounds (bases). Supporting materials in the manufacture of soap are used to increase the quality of soap products, both of useful value and of attractiveness. Supporting materials commonly used in the process of making soap include sodium chloride, sodium carbonate, sodium phosphate, perfume, and dyes.

Soap is made by mixing NaOH / KOH solution with oil or fat. Through chemical reactions,

NaOH / KOH converts Oil / Fat to Soap. This process is called Saponification.
The saponification reaction using alkali is a triglyceride reaction with an alkali (NaOH or KOH) that produces soap and glycerin. The saponizing reaction can be written as follows:

Soap or saponification-making reactions produce soap as the main product and glycerin as byproducts. Glycerin as a by-product also has a selling point. Soap is a salt formed from fatty acids and alkalis. Low molecular weight soaps will be easier to dissolve and have a harder soap structure. The soap has a high solubility in water, but the soap does not dissolve into smaller particles, but dissolves in the form of ions.

Soap is generally known in two forms, liquid soap and solid soap. The main difference between these two forms of soap is the alkali used in the soap-making reaction. Solid soap uses sodium hydroxide / caustic soda (NaOH), whereas liquid soap uses potassium hydroxide (KOH) as alkali. In addition, the type of oil used also affects the form of the resulting soap. Coconut oil will produce soap that is harder than soybean oil, peanut oil, and cotton seed oil. 

The superiority of solid soap in other types of soap appe is solid soap has a good glycerine content for those who have eczema skin problems. But solid soap has higher pH levels. Therefore, solid soap is easier to make the skin dry. This dry skin makes healing slow when the skin is injured. Even so, lately there is a solid soap began to be produced that contains neutral pH so as not to dry the skin again. And also the solid soap has a lower level of pollution so it will not be too dangerous to other animals in the gutter. Actually the waters in this ditch will mostly flow to one place then the water is used by pdam to be clarified and then used for resale to the consumer. This thing Actually that causes pdam have difficulty to purify the water so that in the end much water in many cities now become unfit to drink. Based on the writing of Neo ALFIANNOER's work on the process of making solid soap as follows: 

Soaps are made from fat (animal), oil (vegetable) or fatty acids (fatty acids) which are reacted with an inorganic base that is water soluble. Usually used caustic soda / caustic soda (NaOH) or KOH (potassium hydroxide) is also a frequent alternative, depending on the specific soap that is desired. Soap reaction products with sodium hydroxide (NaOH) are usually harder than the use of Potassium Hydroxide (KOH).
This reaction is commonly called saponification reaction (saponification reaction).

Oil + 3 NaOH -> 3 Soap + Glycerol

In addition to the above reactions the soap can also be generated from the neutralization reaction of Fatty Acid (FA), but here is only obtained soap in the absence of Glycerin (Glycerol), because during the process of making Fatty Acid, glycerol has been separated separately.

FA + NaOH -> Soap + Water

Initially, the saponification process was still done by the cooking / boiling method per batch of kettle (not continuous), but after World War II continuous process development continued to be done. And the continuous process is now more widely used, because in addition to more flexible, and faster also more economical.
Both of the above processes still produce soap is still raw liquid (hot), commonly called neat soap, in addition to produce other side products of glycerol in the form of spent lye which is then processed further in the glycerol unit. Glycerol is the main material in the food industry, cosmetics, medicine etc.
Well neat soap is then dried in the drier unit until it reaches the form of pellets (solid granules), where the amount of water content in the form of pellets is arranged according to the needs of the desired soap specifications. These granules are then mixed in the mixer (amalgamator) with other additives such as dyes, perfume, softener, etc. The mixture is then extruded (suppressed) through the plodder resulting in a bar of soap which is then cut into the cutting machine and into the molding process at the stamping machine / press into certain forms, then then packed in the packaging unit.
The process is usually for soap soap type, but for laundry soap the stage is shorter, only until cutting machine, where in cutter unit is usually equipped with mold to make brand soap and then in pack.
Another case with Sherly Ambarwati who also explained about making soap. According to her make bath soap is easy as long as know how. In principle there are 3 ways to make bath soap.